Manufacture of electric lamps



(No Model.) v

' H;..& P. G. A. SCHULZE-BERGB.

MANUFACTURE OF ELECTRIC LAMPS.

No. 506,733. Patented 001;.41'7, 1893 w/nv ss s.- I INVENTOHS. W; W BY ATTOHNEY.

UNITED STATES PATENT OFFICE.

HERMANN SCHULZE-BERGE AND FRANZ GEORG ALEXANDER SGHULZE- BERGE, OF BROOKLYN, NEW YORK.

MANUFACTURE OF ELECTRIC LAMPS.

SPECIFICATION forming part of Letters Patent No. 506,733, dated October 17, 1893. Application filed March 23, 1893. erial No. 467,365. (No specimens.)

To all whom it may concern:

Be it known that we, HERMANN SCHULZEe BERGE and FRANZ GEoRG ALEXANDER SCHULZE-BERGE, subjects of the Emperor of Germany, and residents of the city of Brooklyn, county of Kings, State of New York, have invented a new and useful Improvement in the Manufacture of Electric Lamps, of which the following is a specification- Our invention refers to the manufacture of electric lamps, and its object is a system for detecting leaky lamp bulbs in the process of exhausting the air.

In the drawings accompanying this descriplion Figure 1 shows a number of incandescent lamp bulbs, each of which is connected to the exhaust pipe by a U shaped tube. In Fig. 2 several lamp bulbs are joined to a common tube, the latter one being a branch of the exhaust pipe. Fig. 3 is a modification of the arrangement shown in Fig. 2.

Similar letters refer to similar parts.

In exhausting electric lamp bulbs two different methods are used. Either every individual lamp is exhausted by a separate pump, or several lamp bulbs are jointly exhausted by a common pump. In the latter case a difficulty arises if there is among the lamp bulbs connected to one pump a leakybulb,because it is generally difficult to decide, which is the leaky one. The usual way of finding it out is often connected with considerable loss of time and with expense for the manufacturer. It is the purpose of our invention to remove this difficulty and to furnish simple means for detecting leaky lamps in a group con nected to a common pump or vacuum chamber. Forthispurposeweinterposeadjustable manometers between the lamps to be exhausted and the vacuum chamber into which their air is discharged.

In Fig. 1 a manometer is interposed between every individual lamp bulb L and the exhaust pipe E. To one arm 0 of the manometer the incandescent lamp bulb L is airtightly connected, while the other arm B leads to the exhaust pipe E. The tube T dips into mercury which'is supplied to the tube V from reservoir R by tube S. The reservoir R is connected to S by a flexible tube F. When a vacuum is created in the exhaust pipe, mercury rises up in tube T, and the length of this tube is such, that even when a perfect vacuum is produced, still the mercury column does not obstruct the passage ways between the lamp bulbs and the exhaust pipe, but only rises, for instance, to the level marked X. It then it is desired to test the air-tightness of the lamp bulbs, vessel It is raised so as to make the mercury rise up into the shanks B and O of the manometers to the level marked Z and toclose the passageways between the lamp bulbs and the exhaust pipe. If all bulbs are airtight the level of the mercury will remain the same in the shanks 0 connected to the bulbs. In case however a lamp bulb is leaky, the alteration of air pressure occurring in the same will be indicated by the depression of the mercury level in the shank C to which that lamp bulb is connected. Thus the leaky lamp is manifested and can easily be sealed off and removed. By this arrangement all the manometers are supplied with mercury simultaneously by simply raising the vessel R, and by lowering this vessel the manometers are emptied again.

If the tubes T are connected airtightly to tubes V, the raising or lowering of the liquid column contained in the same can be effected by increasing or decreasing the air pressure acting upon the mercury in R by an air pump or other suitable. means. In fact if this air pressure is properly regulated, the tubes T need not be of barometric height, but may be considerably shortened.

It hardly is necessary to mention that instead of mercury other liquids which are not objectionable to the nature of the lamp can be used.

The principle illustrated by Fig. 2 is essentially the same as that of Fig. 1, but here a manometer is shown, one arm 0' of which is connected to a plurality of lamp bulbs, while the other arm B leads to the exhaust pipe E. If the vacuum is produced and then the mercury raised to mark Y, the manometer will indicate whether the whole group of lamp bulbs connected to it, considered as a unit, contains a leak. Raising the mercury to the level marked Z will allow to eventually detectany single leaky bulb.

In Fig. 3 a number of lamp bulbs are connected to the arm 0 of the manometer byan airtight joint K. Also here the manometer may be used to test the airtightness as well of the whole group as of a single lamp bulb by raising the mercury level from X to Y or Z The arrangement of the adjustable mawish it understood that by the term adjust-- able manometeras used in this specification and in the claims we designate a manometer the liquid of which may be introduced or: withdrawn at will or adjusted to any suitable] height.

What we claim isinterposed between said lamp bulb and the vacuum chamber,substantially as and for the purpose described.

2. A system for detecting any leaky lamp bulbin a plurality of electric lamp bulbs connected to a common vacuum chamber, consistin g in the combination of every lamp bulb to be tested with an adjustable manometer interposed between said lamp bulb and the vacuum chamber, and a common reservoir adapted to supply the mercury to the manometers simultaneously, substantially as and for the purpose described.

'3. In a system for exhausting electric lamp bulbs adjustable manometers interposed between the vacuum chamber and the pipes carrying the lamp bulbs or groups of lamp bulbs to be exhausted, substantially as and for the purpose described.

4:. In a system for exhausting electric lamp bulbs adjustable manometers interposed between the vacuum chamber and the pipes carrying the lamp bulbs, said adjustable manometers being adapted aswell to control the passageways between the vacuum chamber and said pipes, as the passageways leading from said pipes to the single lamp bulbs to be tested, substantially as and for the purpose described.

5. In a system for exhausting electric lamp bulbs a plurality'of lamp "bulbs'connected t0 the vacuum chamber by-adjustable manometers adapted to indicate any alteration of 1. A-system for detecting any leaky lamp bu lbin'a plurality of electric lamp bulbs con-.1 ne'cted to a common vacuum chamber, con-j 'sistin'g in the combination of everylamp bulb to'be tested'with an adjustable manometer air pressure occurring in any of the bulbs, substantially as and for the purpose described.

In'testimony that we claim the foregoing as our invention we have signed ou'rnames, in presence of two witnesses, this 18th day of "March, 1893.

H'ERMANN SCHULZE-BERGE. FRANZ GEORG ALEXANDER SGHUliZE-BERGE. Witnesses:

FREDERICK CHARLES NlBLO, WM. SWANSBORO. 

